U.S. patent application number 16/756502 was filed with the patent office on 2020-09-10 for method for reducing low speed pre-ignition.
The applicant listed for this patent is SHELL OIL COMPANY. Invention is credited to Anindya Kumar GHOSAL, Edward Carl NELSON, Vivek Raja RAJ MOHAN, Joseph Michael RUSSO.
Application Number | 20200283691 16/756502 |
Document ID | / |
Family ID | 1000004900135 |
Filed Date | 2020-09-10 |
United States Patent
Application |
20200283691 |
Kind Code |
A1 |
RAJ MOHAN; Vivek Raja ; et
al. |
September 10, 2020 |
METHOD FOR REDUCING LOW SPEED PRE-IGNITION
Abstract
Use of an unleaded gasoline fuel composition for reducing the
occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition
internal combustion engine, wherein the unleaded gasoline fuel
composition comprises a gasoline base fuel and detergent additive
package, wherein the detergent additive package comprises a Mannich
base detergent mixture, wherein the mixture comprises a first
Mannich base detergent component derived from a di- or polyamine
and a second Mannich base detergent component derived from a
monoamine, wherein the weight ratio of the first Mannich base
detergent to the second Mannich base detergent mixture ranges from
about 1:6 to about 3:1, and wherein the spark-ignition internal
combustion engine is lubricated with a lubricant composition
comprising from 1200 ppmw to 3000 ppmw of calcium, based on the
total lubricant composition.
Inventors: |
RAJ MOHAN; Vivek Raja;
(Cypress, TX) ; NELSON; Edward Carl; (Katy,
TX) ; RUSSO; Joseph Michael; (Houston, TX) ;
GHOSAL; Anindya Kumar; (Dubai, AE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHELL OIL COMPANY |
HOUSTON |
TX |
US |
|
|
Family ID: |
1000004900135 |
Appl. No.: |
16/756502 |
Filed: |
October 16, 2018 |
PCT Filed: |
October 16, 2018 |
PCT NO: |
PCT/US2018/056008 |
371 Date: |
April 16, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62573723 |
Oct 18, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10L 2250/04 20130101;
C10L 2200/0423 20130101; C10L 2270/023 20130101; C10L 1/143
20130101; C10L 1/224 20130101; C10L 1/2222 20130101; C10L 1/1616
20130101; C10L 1/1985 20130101 |
International
Class: |
C10L 1/14 20060101
C10L001/14; C10L 1/224 20060101 C10L001/224; C10L 1/198 20060101
C10L001/198; C10L 1/222 20060101 C10L001/222; C10L 1/16 20060101
C10L001/16 |
Claims
1. An unleaded gasoline fuel composition for reducing the
occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition
internal combustion engine, wherein the unleaded gasoline fuel
composition comprises: a gasoline base fuel, and a detergent
additive package, wherein the detergent additive package comprises
a Mannich base detergent mixture, wherein the Mannich base
detergent mixture comprises a first Mannich base detergent
component derived from a di- or polyamine and a second Mannich base
detergent component derived from a monoamine, wherein the weight
ratio of the first Mannich base detergent to the second Mannich
base detergent mixture ranges from about 1:6 to about 3:1, and
wherein the spark-ignition internal combustion engine is lubricated
with a lubricant composition comprising from 1200 ppmw to 3000 ppmw
of calcium, based on the total lubricant composition.
2. The unleaded gasoline fuel composition according to claim 1
wherein the detergent package further comprises a carrier fluid,
preferably selected from the group consisting of a polyether monool
and polyether polyol, wherein the weight ratio of carrier fluid to
Mannich base detergent mixture ranges from about 0.25:1 to about
1:1.
3. The unleaded gasoline fuel composition according to claim 2
wherein the weight ratio of the first Mannich base detergent to the
second Mannich base detergent ranges from about 1:1 to about
1:3.
4. The unleaded gasoline fuel composition according to claim 1
wherein the detergent package further comprises an antiwear
component selected from a hydrocarbyl amide and a hydrocarbyl
imide.
5. The unleaded gasoline fuel composition according to claim 1
wherein the detergent additive package further comprises a
succinimide detergent, wherein the weight ratio of succinimide
detergent to Mannich base detergent mixture ranges from about
0.04:1 to about 0.2:1.
6. The unleaded gasoline fuel composition according to claim 1
wherein the unleaded gasoline fuel composition comprises from about
23 ppm to 2000 ppm by weight of the detergent additive package.
7. The unleaded gasoline fuel composition according to claim 1
wherein the detergent additive package is present in the form of an
additive concentrate which comprises the detergent additive package
and an antiwear component selected from a hydrocarbyl amide and a
hydrocarbyl imide.
8. The unleaded gasoline fuel composition according to claim 7
wherein the unleaded gasoline fuel composition comprises from about
23 ppm to about 2000 ppm by weight of the additive concentrate.
9. The unleaded gasoline fuel composition according to claim 1
wherein the first Mannich base detergent and the second Mannich
base detergent are derived from polyisobutenyl phenol and wherein
the polyisobutenyl group has a molecular weight ranging from 500 to
1000 Daltons, as determined by gel permeation chromatography.
10. An unleaded gasoline fuel composition for reducing the
occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition
internal combustion engine, wherein the unleaded gasoline fuel
composition comprises: a major amount of gasoline base fuel, a
minor amount of a first Mannich base detergent derived from a di-
or polyamine and a second Mannich base detergent derived from a
monoamine, an antiwear component selected from a hydrocarbyl amide
and a hydrocarbyl imide, a polyether carrier fluid, and a
succinimide detergent, wherein the weight ratio of the first
Mannich base detergent to the second Mannich base detergent mixture
ranges from about 1:6 to about 3:1, and wherein the spark-ignition
internal combustion engine is lubricated with a lubricant
composition comprising from 1200 ppmw to 3000 ppmw of calcium,
based on the total lubricant composition.
11. The method for reducing the occurrence of Low Speed
Pre-Ignition (LSPI) in an internal combustion engine, the method
comprising supplying to the engine a fuel composition comprising an
unleaded gasoline fuel composition comprising a detergent additive
package wherein the detergent additive package comprises Mannich
base detergent mixture, wherein the mixture comprises a first
Mannich base detergent component derived from a di- or polyamine
and a second Mannich base detergent component derived from a
monoamine, wherein the weight ratio of the first Mannich base
detergent to the second Mannich base detergent mixture ranges from
about 1:6 to about 3:1, and wherein the spark-ignition internal
combustion engine is lubricated with a lubricant composition
comprising from 1200 ppmw to 3000 ppmw of calcium, based on the
total lubricant composition.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 62/573,723 filed Oct. 18, 2017, the entire
disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for reducing low
speed pre-ignition in a spark-ignition internal combustion
engine.
BACKGROUND OF THE INVENTION
[0003] Under ideal conditions, normal combustion in a conventional
spark-ignited engine occurs when a mixture of fuel and air is
ignited within the combustion chamber inside the cylinder by the
production of a spark originating from a spark plug. Such normal
combustion is generally characterized by the expansion of the flame
front across the combustion chamber in an orderly and controlled
manner.
[0004] However, in some instances, the fuel/air mixture may be
prematurely ignited by an ignition source prior to the spark plug
firing, thereby resulting in a phenomenon known as pre-ignition.
Pre-ignition is undesirable as it typically results in the presence
of greatly increased temperatures and pressures within the
combustion chamber, which may have a significant, negative impact
on the overall efficiency and performance of an engine.
Pre-ignition may cause damage to the cylinders, pistons and valves
in the engine and in some instances may even culminate in engine
failure.
[0005] Recently, low-speed pre-ignition ("LSPI") has been
recognized amongst many original equipment manufacturers ("OEMs")
as a potential problem for highly boosted, down-sized
spark-ignition engines. Contrary to the pre-ignition phenomenon
observed in the late 50's at high speeds, LSPI typically occurs at
low speeds and high loads. LSPI is a constraint that restricts
improvements in torque at low engine speeds, which could impact
fuel economy and drivability. The occurrence of LSPI may ultimately
lead to so-called "monster knock" or "mega-knock" where potentially
devastating pressure waves can result in severe damage to the
piston and/or cylinder. As such, any technology that can mitigate
the risk of pre-ignition, including LSPI, would be highly
desirable.
[0006] There are multiple mechanisms leading to LSPI events
discussed in the literature. One of those mechanisms involves
ignition of the flaked-off deposits present inside the combustion
chamber (e.g. around the piston crevice region or on the injector)
leading to LSPI events while another mechanism is based on the
ignition of oil droplets inside the combustion chamber. It could be
a combination of these two mechanisms (deposits and oil droplets)
that results in LSPI or a yet to be determined mechanism.
[0007] It has been found that LSPI is more common in engines, such
as modern turbocharged engines, that operate using an engine oil
with high calcium content and a market-average gasoline fuel. Most
commercial engine oils currently available in the market have high
calcium content, ranging from 1200 ppm to 3000 ppm. Typically, as
mentioned above, this LSPI phenomenon is common in the high torque,
low speed operating conditions. Most Original Equipment
Manufacturers (OEMs) calibrate their engine management systems to
avoid engine operation in these regimes to prevent LSPI from
occurring. However, operating in these regimes would potentially
give the OEMs additional opportunity to decrease fuel
consumption.
[0008] One solution to the problem of LSPI is to formulate engine
oils such that they have a new composition. Examples of those
methods can be found in WO2015/171978A1, WO2016/087379A1,
WO2015/042341A1. One such solution is to formulate engine oils
having a very low calcium content (<100 ppm). The effects of
lower calcium content in the engine oils in lowering LSPI
occurrences have been described in SAE 2016-01-2275. Such a
formulation potentially modifies the chemical pathways in terms of
the oil droplets that lead to LSPI. However, most current
commercial engine oils have high calcium content and therefore it
would be desirable to come up with an alternative solution for the
problem of LSPI without having to reformulate the engine oil
formulation.
[0009] It has now been found by the present inventors that by using
a gasoline formulation which comprises a certain type of detergent
additive package and/or certain detergent additive components, a
surprising reduction in LSPI events can be achieved, especially in
the case when used in engines which are lubricated with engine oils
having high levels of calcium.
SUMMARY OF THE INVENTION
[0010] According to the present invention there is provided the use
of an unleaded gasoline fuel composition for reducing the
occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition
internal combustion engine, wherein the unleaded gasoline fuel
composition comprises a gasoline base fuel and a detergent additive
package, wherein the detergent additive package comprises a Mannich
base detergent mixture, wherein the mixture comprises a first
Mannich base detergent component derived from a di- or polyamine
and a second Mannich base detergent component derived from a
monoamine, wherein the weight ratio of the first Mannich base
detergent to the second Mannich base detergent mixture ranges from
about 1:6 to about 3:1, and wherein the spark-ignition internal
combustion engine is lubricated with a lubricant composition
comprising from 1200 ppmw to 3000 ppmw of calcium, based on the
total lubricant composition.
[0011] According to the present invention there is further provided
the use of an unleaded gasoline fuel composition for reducing the
occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition
internal combustion engine, wherein the unleaded gasoline fuel
composition comprises a major amount of gasoline base fuel, a minor
amount of a first Mannich base detergent derived from a di- or
polyamine and a second Mannich base detergent derived from a
monoamine, an antiwear component, preferably selected from a
hydrocarbyl amide and a hydrocarbyl imide, and a polyether carrier
fluid, and optionally a succinimide detergent, wherein the weight
ratio of the first Mannich base detergent to the second Mannich
base detergent mixture ranges from about 1:6 to about 3:1, and
wherein the spark-ignition internal combustion engine is lubricated
with a lubricant composition comprising from 1200 ppmw to 3000 ppmw
of calcium, based on the total lubricant composition.
[0012] According to the present invention there is further provided
a method for reducing the occurrence of Low Speed Pre-Ignition
(LSPI) in an internal combustion engine, the method comprising
supplying to the engine a fuel composition comprising an unleaded
gasoline fuel composition comprising a detergent additive package
wherein the detergent additive package comprises a Mannich base
detergent mixture, wherein the mixture comprises a first Mannich
base detergent component derived from a di- or polyamine and a
second Mannich base detergent component derived from a monoamine,
wherein the weight ratio of the first Mannich base detergent to the
second Mannich base detergent mixture ranges from about 1:6 to
about 3:1, and wherein the spark-ignition internal combustion
engine is lubricated with a lubricant composition comprising from
1200 ppmw to 3000 ppmw of calcium, based on the total lubricant
composition.
[0013] The features and advantages of the present invention will be
apparent to those skilled in the art. While numerous changes may be
made by those skilled in the art, such changes are within the
spirit of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Accordingly, the disclosure herein provides the use of an
unleaded gasoline fuel composition comprising a specified additive
package or comprising a certain combination of specified additive
components for reducing the occurrence of Low Speed Pre-Ignition
(LSPI) in a spark-ignition internal combustion engine.
[0015] The level of occurrence of pre-ignition in a spark-ignited
engine may be assessed using any suitable method. In general, such
a method may involve running a spark-ignited engine using the
relevant fuel and/or lubricant composition, and monitoring changes
in engine pressure during its combustion cycles, i.e., changes in
pressure versus crank angle. A pre-ignition event will result in an
increase in engine pressure before sparking: this may occur during
some engine cycles but not others. Instead, or in addition to,
changes in engine performance may be monitored, for example by
maximum attainable brake torque, engine speed, intake pressure
and/or exhaust gas temperature. Instead, or in addition to, a
suitably experienced driver may test-drive a vehicle which is
driven by the spark-ignited engine, to assess the effects of a
particular fuel and/or lubricant composition on, for example, the
degree of engine knock or other aspects of engine performance.
Instead, or in addition to, levels of engine damage due to
pre-ignition, for example due to the associated engine knock, may
be monitored over a period of time during which the spark-ignited
engine is running using the relevant fuel and/or lubricant
composition.
[0016] A reduction in the occurrence of pre-ignition may be a
reduction in the number of engine cycles at which pre-ignition
events occur or a reduction in the rate at which pre-ignition
events occur within the engine, and/or in the severity of the
pre-ignition events which occur (for example, the degree of
pressure change which they cause). It may be manifested by a
reduction in one or more of the effects which pre-ignition can have
on engine performance, for example impairment of brake torque or
inhibition of engine speed. It may be manifested by a reduction in
the amount or severity of engine knock, in particular by a
reduction in, or elimination of, "mega knock". Preferably, in the
present invention, a reduction in the occurrence of pre-ignition is
a reduction in the number of engine cycles in which pre-ignition
events occur.
[0017] Since pre-ignition, particularly if it occurs frequently,
can cause significant engine damage, the fuel compositions
disclosed herein may also be used for the purpose of reducing
engine damage and/or for the purpose of increasing engine
longevity.
[0018] The uses and methods of the present invention may be used to
achieve any degree of reduction in the occurrence of pre-ignition
in the engine, including reduction to zero (i.e., eliminating
pre-ignition). It may be used to achieve any degree of reduction in
a side effect of pre-ignition, for example engine damage. It may be
used for the purpose of achieving a desired target level of
occurrence or side effect. The method and use herein preferably
achieves a 5% reduction or more in the occurrence of pre-ignition
in the engine, more preferably a 10% reduction or more in the
occurrence of pre-ignition in the engine, even more preferably a
15% reduction or more in the occurrence of pre-ignition in the
engine, and especially a 30% reduction or more in the occurrence of
pre-ignition in the engine.
[0019] Examples of suitable methods for measuring Low Speed
Pre-Ignition events can be found in the following SAE papers: SAE
2014-01-1226, SAE 2011-01-0340, SAE 2011-01-0339 and SAE
2011-01-0342. Another example of a suitable method for measuring
Low Speed Pre-Ignition events is that described in the Examples
hereinbelow.
[0020] Fuel compositions for use herein generally comprise a
gasoline base fuel and optionally one or more fuel additives in
addition to the detergent additive package or the specified
combination of additive components described herein.
[0021] In one aspect of the present invention, the unleaded
gasoline fuel composition comprises a gasoline base fuel and a
detergent additive package. The detergent additive package is
typically used at a concentration from 6 PTB (23 ppmw) to 528 PTB
(2000 ppmw), preferably from 8 PTB (30 ppmw) to 300 PTB (1125
ppmw), more preferably from 30 PTB (113 ppmw) to 250 PTB (942 ppmw)
(where PTB stands for pounds of additive per thousand barrels of
gasoline).
[0022] The detergent additive package for use herein comprises a
Mannich base detergent mixture that comprises a first Mannich base
detergent component derived from a di- or polyamine and a second
Mannich base detergent component derived from a monoamine, wherein
the weight ratio of the first Mannich base detergent to the second
Mannich base detergent in the mixture ranges from about 1:6 to
about 3:1, such as from 1:4 to 2:1 or from 1:3 to 1:1. Suitable
detergent additive packages for use herein are disclosed in
US2016/0289584, incorporated herein by reference.
[0023] In one embodiment herein, a suitable fuel additive package
comprises (a) a first Mannich base detergent component derived from
a di- or polyamine, (b) a second Mannich base detergent component
derived from a monoamine, (c) an antiwear component, and (d)
optionally, a carrier fluid component selected from the group
consisting of a polyether monool and polyether polyol. The ratio
weight of the first Mannich base detergent to the second Mannich
base detergent in the fuel additive package ranges from about 1:6
to about 3:1, such as from 1:4 to 2:1, or from 1:3 to 1:1.
[0024] In another aspect of the present invention, the gasoline
fuel composition comprises a combination of Mannich base detergent
additives instead of a detergent additive package. In this aspect
of the present invention, the Mannich base detergent additives are
added to the gasoline base fuel, either by premixing the individual
detergent additives together, optionally together with one or more
antiwear additives and/or one or more succinimde detergents and/or
one or more carrier fluids, and then adding the premix to the
gasoline base fuel, or by adding the individual detergent additives
and the individual antiwear additives and carrier fluids, directly
to the gasoline base fuel.
Mannich Base Detergents
[0025] The Mannich base detergents useful in the present invention
are the reaction products of an alkyl-substituted hydroxy aromatic
compound, an aldehyde and an amine. The alkyl-substituted
hydroxyaromatic compound, aldehyde and amine used in making the
Mannich detergent reaction products described herein may be any
such compounds known and applied in the art, provided the Mannich
based detergents include at least a first Mannich base detergent
derived from a di- or polyamine and at least a second Mannich base
detergent derived from a dialkyl monoamine.
[0026] Representative alkyl-substituted hydroxyaromatic compounds
that may be used in forming the Mannich base reaction products are
polypropylphenol (formed by alkylating a phenol with
polypropylene), polybutylphenols (formed by alkylating a phenol
with polybutenes and/or polyisobutylene) and
polybutyl-co-polypropylphenol (formed by alkylating phenol with a
copolymer of butylene and/or butylene and propylene). Other similar
long-chain alkylphenols may also be used. Examples include phenols
alkylated with copolymers of butylene and/or isobutylene and/or
propylene, and one or more mono-olefinic co-monomers
copolymerizable therewith (e.g., ethylene, 1-pentene, 1-hexene,
1-octene, 1-decene, etc.) where the copolymer molecule contains at
least 50% by weight, of butylene and/or isobutylene and/or
propylene units. The comonomers polymerized with propylene,
butylenes and/or isobutylene may be aliphatic and may also contain
non-aliphatic groups, e.g., styrene, o-methylstyrene,
p-methylstyrene, di-vinyl benzene and the like. Thus in any case
the resulting polymers and copolymers used in forming the
alkyl-substituted hydroxyaromatic compounds are substantially
aliphatic hydrocarbon polymers. In one embodiment herein,
polybutylphenol (formed by alkylating a phenol with polybutylene)
is used in forming the Mannich base detergents. Unless otherwise
specified herein, the term "polybutylene" is used in a generic
sense to include polymers made from "pure" or "substantially pure"
1-butene or isobutene, and polymers made from mixtures of two or
all three of 1-butene, 2-butene and isobutene. Commercial grades of
such polymers may also contain insignificant amounts of other
olefins. So-called high reactivity polybutylenes having relatively
high proportions of polymer molecules having a terminal vinylidene
group, formed by methods such as described, for example, in U.S.
Pat. No. 4,152,499 and W. German Offenlegungsschrift 29 04 314, are
also suitable for use in forming the long chain alkylated phenol
reactant.
[0027] The alkylation of the hydroxyaromatic compound is typically
performed in the presence of an alkylating catalyst at a
temperature in the range of about 50.degree. to about 200.degree.
C. Acidic catalysts are generally used to promote Friedel-Crafts
alkylation. Typical catalysts used in commercial production include
sulfuric acid, BF.sub.3, aluminum phenoxide, methanesulphonic acid,
cationic exchange resin, acidic clays and modified zeolites.
[0028] The long chain alkyl substituents on the benzene ring of the
phenolic compound are derived from polyolefin having a number
average molecular weight (MW) of from about 500 to about 3000
Daltons (preferably from about 500 to about 2100 Daltons) as
determined by gel permeation chromatography (GPC). It is also
desirable that the polyolefin used have a polydispersity (weight
average molecular weight/number average molecular weight) in the
range of about 1 to about 4 (suitably from about 1 to about 2) as
determined by GPC.
[0029] The Mannich detergents may be made from a long chain
alkylphenol. However, other phenolic compounds may be used
including high molecular weight alkyl-substituted derivatives of
resorcinol, hydroquinone, catechol, hydroxydiphenyl, benzylphenol,
phenethylphenol, naphthol, tolylnaphthol, among others.
Particularly suitable for the preparation of the Mannich
condensation products are the polyalkylphenol and polyalkylcresol
reactants, e.g., polypropylphenol, polybutylphenol,
polypropylcresol, polyisobutylcresol, and polybutylcresol, wherein
the alkyl group has a number average molecular weight of about 500
to about 2100, while the most suitable alkyl group is a polybutyl
group derived from polybutylene having a number average molecular
weight in the range of about 800 to about 1300 Daltons.
[0030] The configuration of the alkyl-substituted hydroxyaromatic
compound is that of a para-substituted monoalkylphenol or a
para-substituted mono-alkyl ortho-cresol. However, any alkylphenol
readily reactive in the Mannich condensation reaction may be used.
Thus, Mannich products made from alkylphenols having only one ring
alkyl substituent, or two or more ring alkyl substituents are
suitable for use in making the Mannich base detergents described
herein. The long chain alkyl substituents may contain some residual
unsaturation, but in general, are substantially saturated alkyl
groups. Long chain alkyl phenols, according to the disclosure,
include cresol. Representative reactants include, but are not
limited to, linear, branched or cyclic alkylene monoamines and di-
or polyamines having at least one suitably reactive primary or
secondary amino group in the molecule. Other substituents such as
hydroxyl, cyano, amido, etc., may be present in the amine compound.
In one embodiment, the first Mannich base detergent is derived from
an alkylene di- or polyamine Such di- or polyamines may include,
but are not limited to, polyethylene polyamines, such as
ethylenediamine, diethylenetriamine, triethylenetetramine,
tetraethylenepentamine, pentaethylenehexamine,
hexaethyleneheptamine, heptaethyleneoctamine, octaethylenenonamine,
nonaethylenedecamine, decaethyleneundecamine and mixtures of such
amines having nitrogen contents corresponding to alkylene
polyamines of the formula H.sub.2N-(A-NH--).sub.nH, where A is
divalent ethylene and n is an integer of from 1 to 10. The alkylene
polyamines may be obtained by the reaction of ammonia and
dihaloalkanes, such as dichloro alkanes. Thus, the alkylene
polyamines obtained from the reaction of 2 to 11 moles of ammonia
with 1 to 10 moles of dichloro alkanes having 2 to 6 carbon atoms
and the chlorines on different carbon atoms are suitable alkylene
polyamine reactants.
[0031] In one embodiment, the first Mannich base detergent is
derived from an aliphatic linear, branched or cyclic diamine or
polyamine having one primary or secondary amino group and one
tertiary amino group in the molecule. Examples of suitable
polyamines include N,N,N'',N''-tetraalkyl-dialkylenetriamines (two
terminal tertiary amino groups and one central secondary amino
group), N,N,N'',N''-tetraalkyltrialkylenetetramines (one terminal
tertiary amino group, two internal tertiary amino groups and one
terminal primary amino group),
N,N,N,N'',N'''-pentaalkyltrialkylene-tetramines (one terminal
tertiary amino group, two internal tertiary amino groups and one
terminal secondary amino group), N,N-dihydroxyalkyl-alpha,
omega-alkylenediamines (one terminal tertiary amino group and one
terminal primary amino group), N,N,N'-trihydroxy-alkyl-alpha,
omega-alkylenediamines (one terminal tertiary amino group and one
terminal secondary amino group),
tris(dialkylaminoalkyl)aminoalkylmethanes (three terminal tertiary
amino groups and one terminal primary amino group), and like
compounds, wherein the alkyl groups are the same or different and
typically contain no more than about 12 carbon atoms each, and
which suitably contain from 1 to 4 carbon atoms each. In one
embodiment, the alkyl groups of the polyamine are methyl and/or
ethyl groups. Accordingly, the polyamine reactants may be selected
from N,N-dialkylalpha, omega-alkylenediamine, such as those having
from 3 to about 6 carbon atoms in the alkylene group and from 1 to
about 12 carbon atoms in each of the alkyl groups. A particularly
useful polyamine is N,N-dimethyl-1-,3-propanediamine and N-methyl
piperazine.
[0032] Examples of polyamines having one reactive primary or
secondary amino group that can participate in the Mannich
condensation reaction and at least one sterically hindered amino
group that cannot participate directly in the Mannich condensation
reaction to any appreciable extent include
N-(tert-butyl)-1,3-propanediamine, N-neopentyl-1,3-propanediamine,
N-(tert-butyl)-1-methyl-1,2-ethanediamine,
N-(tert-butyl)-1-methyl-1,3-propanediamine, and
3,5-di(tert-butyl)aminoethyl-1-piperazine.
[0033] The second Mannich base detergent may be derived from an
alkyl-monoamine, that includes, without limitation, a di-alkyl
monoamine such as methylamine, dimethyl amine, ethylamine,
di-ethylamine, propylamine, isopropylamine, dipropyl amine,
di-isopropyl amine, butylamine, isobutylamine, di-butyl amine,
di-isobutylamine, pentylamine, dipentyl amine, neopentylamine,
di-neopentyl amine, hexylamine, dihexyl amine, heptylamine,
diheptyl amine, octylamine, dioctyl amine, 2-ethylhexylamine,
di-2-ethylhexyl amine, nonylamine, dinonyl amine, decylamine,
didecyl amine, dicyclohexylamine, and the like.
[0034] Representative aldehydes for use in the preparation of the
Mannich base products include the aliphatic aldehydes such as
formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde,
valeraldehyde, caproaldehyde, heptaldehyde, stearaldehyde. Aromatic
aldehydes which may be used include benzaldehyde and
salicylaldehyde. Illustrative heterocyclic aldehydes for use herein
are furfural and thiophene aldehyde, etc. Also useful are
formaldehyde-producing reagents such as paraformaldehyde, or
aqueous formaldehyde solutions such as formalin. A particularly
suitable aldehyde may be selected from formaldehyde and
formalin.
[0035] The condensation reaction among the alkylphenol, the
specified amine(s) and the aldehyde may be conducted at a
temperature in the range of about 40.degree. C. to about
200.degree. C. The reaction may be conducted in bulk (no diluent or
solvent) or in a solvent or diluent. Water is evolved and may be
removed by azeotropic distillation during the course of the
reaction. Typically, the Mannich reaction products are formed by
reacting the alkyl-substituted hydroxyaromatic compound, the amine
and aldehyde in the molar ratio of 1.0:0.5-2.0:1.0-3.0,
respectively.
[0036] Suitable Mannich base detergents for use in the disclosed
embodiments include those detergents taught in U.S. Pat. Nos.
4,231,759, 5,514,190, 5,634,951, 5,697,988, 5,725,612, 5,876,468
and 6,800,103, the disclosures of which are incorporated herein by
reference.
[0037] When formulating the fuel compositions used herein, a
mixture of the Mannich base detergents is used. The mixture of
Mannich base detergents includes a weight ratio of from about 1:6
to about 3:1 of the first Mannich base detergent to the second
Mannich base detergent. In another embodiment, the mixture of
Mannich base detergents includes a weight ratio of from about 1:4
to about 2:1, such as from about 1:3 to about 1:1, of the first
Mannich base detergent to the second Mannich base detergent. The
total amount of Mannich base detergent in a gasoline fuel
composition according to the disclosure may range from about 10 to
about 400 parts per million by weight based on a total weight of
the fuel composition.
[0038] An optional component of the fuel compositions and/or
additive package(s) described herein is a succinimide detergent.
The succinimide detergent suitable for use in various embodiments
of the disclosure may impart a dispersant effect on the fuel
composition when added in an amount effective for that purpose. The
presence of the succinimide, together with the mixed Mannich base
detergents, in the fuel composition is observed to result in
enhanced deposit formation control, relative to the performance of
the succinimide together with either the first or second Mannich
base detergent.
[0039] The succinimide detergents, for example, include alkenyl
succinimides comprising the reaction products obtained by reacting
an alkenyl succinic anhydride acid, acid-ester or lower alkyl ester
with an amine containing at least one primary amine group.
[0040] Suitable succinimide base detergents for use herein include
those disclosed in US2016/0289584, incorporated by reference
herein.
[0041] When the succinimide detergent is present in the fuel
compositions/additive packages herein, the weight ratio of
succinimide detergent to Mannich base detergent mixture preferably
ranges from about 0.04:1 to about 0.2:1.
[0042] In another embodiment, the Mannich base detergent mixture
and the succinimide detergent may be used with a liquid carrier or
induction aid. Such carriers may be of various types, such as for
example liquid poly-alphaolefin oligomers, mineral oils, liquid
poly(oxyalkylene) compounds, liquid alcohols or polyols,
polyalkenes, liquid esters, and similar liquid carriers. Mixtures
of two or more such carriers may be used. Suitable carrier fluids
for use herein include those disclosed in US2016/0289584,
incorporated herein by reference.
[0043] When the carrier fluid is present, the weight ratio of
carrier fluid to Mannich base detergent mixture preferably ranges
from about 0.25:1 to about 1:1.
[0044] The anti-wear component for the fuel compositions, and
additive packages described herein may be selected from a
hydrocarbyl amide and a hydrocarbyl imide.
[0045] In one embodiment, the hydrocarbyl amide is an alkanol amide
derived from diethanol amine and oleic acid. In another embodiment,
the hydrocarbyl imide is a succinimide derived from polyisobutenyl
succinic anhydride and ammonia. In one embodiment, the hydrocarbyl
amide compound may be one or more fatty acid alkanol amide
compounds.
[0046] Suitable anti-wear additives for use herein include those
disclosed in US2016/0289584, incorporated herein by reference.
[0047] If the liquid fuel compositions of the present invention
contain a gasoline base fuel, the liquid fuel composition is a
gasoline fuel composition. The gasoline may be any gasoline
suitable for use in an internal combustion engine of the
spark-ignition (gasoline) type known in the art, including
automotive engines as well as in other types of engine such as, for
example, off road and aviation engines. The gasoline used as the
base fuel in the liquid fuel composition of the present invention
may conveniently also be referred to as `base gasoline`.
[0048] Gasolines typically comprise mixtures of hydrocarbons
boiling in the range from 25 to 230.degree. C. (EN-ISO 3405), the
optimal ranges and distillation curves typically varying according
to climate and season of the year. The hydrocarbons in a gasoline
may be derived by any means known in the art, conveniently the
hydrocarbons may be derived in any known manner from straight-run
gasoline, synthetically-produced aromatic hydrocarbon mixtures,
thermally or catalytically cracked hydrocarbons, hydro-cracked
petroleum fractions, catalytically reformed hydrocarbons or
mixtures of these.
[0049] The specific distillation curve, hydrocarbon composition,
research octane number (RON) and motor octane number (MON) of the
gasoline are not critical.
[0050] Conveniently, the research octane number (RON) of the
gasoline may be at least 80, for instance in the range of from 80
to 110, preferably the RON of the gasoline will be at least 90, for
instance in the range of from 90 to 110, more preferably the RON of
the gasoline will be at least 91, for instance in the range of from
91 to 105, even more preferably the RON of the gasoline will be at
least 92, for instance in the range of from 92 to 103, even more
preferably the RON of the gasoline will be at least 93, for
instance in the range of from 93 to 102, and most preferably the
RON of the gasoline will be at least 94, for instance in the range
of from 94 to 100 (EN 25164); the motor octane number (MON) of the
gasoline may conveniently be at least 70, for instance in the range
of from 70 to 110, preferably the MON of the gasoline will be at
least 75, for instance in the range of from 75 to 105, more
preferably the MON of the gasoline will be at least 80, for
instance in the range of from 80 to 100, most preferably the MON of
the gasoline will be at least 82, for instance in the range of from
82 to 95 (EN 25163).
[0051] Typically, gasolines comprise components selected from one
or more of the following groups; saturated hydrocarbons, olefinic
hydrocarbons, aromatic hydrocarbons, and oxygenated hydrocarbons.
Conveniently, the gasoline may comprise a mixture of saturated
hydrocarbons, olefinic hydrocarbons, aromatic hydrocarbons, and,
optionally, oxygenated hydrocarbons.
[0052] Typically, the olefinic hydrocarbon content of the gasoline
is in the range of from 0 to 40 percent by volume based on the
gasoline (ASTM D1319); preferably, the olefinic hydrocarbon content
of the gasoline is in the range of from 0 to 30 percent by volume
based on the gasoline, more preferably, the olefinic hydrocarbon
content of the gasoline is in the range of from 0 to 20 percent by
volume based on the gasoline.
[0053] Typically, the aromatic hydrocarbon content of the gasoline
is in the range of from 0 to 70 percent by volume based on the
gasoline (ASTM D1319), for instance the aromatic hydrocarbon
content of the gasoline is in the range of from 10 to 60 percent by
volume based on the gasoline; preferably, the aromatic hydrocarbon
content of the gasoline is in the range of from 0 to 50 percent by
volume based on the gasoline, for instance the aromatic hydrocarbon
content of the gasoline is in the range of from 10 to 50 percent by
volume based on the gasoline.
[0054] The benzene content of the gasoline is at most 10 percent by
volume, more preferably at most 5 percent by volume, especially at
most 1 percent by volume based on the gasoline.
[0055] The gasoline preferably has a low or ultra low sulphur
content, for instance at most 1000 ppmw (parts per million by
weight), preferably no more than 500 ppmw, more preferably no more
than 100, even more preferably no more than 50 and most preferably
no more than even 10 ppmw.
[0056] The gasoline also preferably has a low total lead content,
such as at most 0.005 g/l, most preferably being lead free--having
no lead compounds added thereto (i.e. unleaded).
[0057] When the gasoline comprises oxygenated hydrocarbons, at
least a portion of non-oxygenated hydrocarbons will be substituted
for oxygenated hydrocarbons. The oxygen content of the gasoline may
be up to 35 percent by weight (EN 1601) (e.g. ethanol per se) based
on the gasoline. For example, the oxygen content of the gasoline
may be up to 25 percent by weight, preferably up to 10 percent by
weight. Conveniently, the oxygenate concentration will have a
minimum concentration selected from any one of 0, 0.2, 0.4, 0.6,
0.8, 1.0, and 1.2 percent by weight, and a maximum concentration
selected from any one of 5, 4.5, 4.0, 3.5, 3.0, and 2.7 percent by
weight.
[0058] Examples of oxygenated hydrocarbons that may be incorporated
into the gasoline include alcohols, ethers, esters, ketones,
aldehydes, carboxylic acids and their derivatives, and oxygen
containing heterocyclic compounds. Preferably, the oxygenated
hydrocarbons that may be incorporated into the gasoline are
selected from alcohols (such as methanol, ethanol, propanol,
2-propanol, butanol, tert-butanol, iso-butanol and 2-butanol),
ethers (preferably ethers containing 5 or more carbon atoms per
molecule, e.g., methyl tert-butyl ether and ethyl tert-butyl ether)
and esters (preferably esters containing 5 or more carbon atoms per
molecule); a particularly preferred oxygenated hydrocarbon is
ethanol.
[0059] When oxygenated hydrocarbons are present in the gasoline,
the amount of oxygenated hydrocarbons in the gasoline may vary over
a wide range. For example, gasolines comprising a major proportion
of oxygenated hydrocarbons are currently commercially available in
countries such as Brazil and U.S.A., e.g. ethanol per se and E85,
as well as gasolines comprising a minor proportion of oxygenated
hydrocarbons, e.g. E10 and E5. Therefore, the gasoline may contain
up to 100 percent by volume oxygenated hydrocarbons. E100 fuels as
used in Brazil are also included herein. Preferably, the amount of
oxygenated hydrocarbons present in the gasoline is selected from
one of the following amounts: up to 85 percent by volume; up to 70
percent by volume; up to 65 percent by volume; up to 30 percent by
volume; up to 20 percent by volume; up to 15 percent by volume;
and, up to 10 percent by volume, depending upon the desired final
formulation of the gasoline. Conveniently, the gasoline may contain
at least 0.5, 1.0 or 2.0 percent by volume oxygenated
hydrocarbons.
[0060] Examples of suitable gasolines include gasolines which have
an olefinic hydrocarbon content of from 0 to 20 percent by volume
(ASTM D1319), an oxygen content of from 0 to 5 percent by weight
(EN 1601), an aromatic hydrocarbon content of from 0 to 50 percent
by volume (ASTM D1319) and a benzene content of at most 1 percent
by volume.
[0061] Also suitable for use herein are gasoline blending
components which can be derived from a biological source. Examples
of such gasoline blending components can be found in WO2009/077606,
WO2010/028206, WO2010/000761, European patent application nos.
09160983.4, 09176879.6, 09180904.6, and U.S. patent application
Ser. No. 61/312,307.
[0062] Whilst not critical to the present invention, the base
gasoline or the gasoline composition of the present invention may
conveniently include one or more optional fuel additives, in
addition to the essential Mannich detergents mentioned above. The
concentration and nature of the optional fuel additive(s) that may
be included in the base gasoline or the gasoline composition used
in the present invention is not critical. Non-limiting examples of
suitable types of fuel additives that can be included in the base
gasoline or the gasoline composition used in the present invention
include anti-oxidants, corrosion inhibitors, antiwear additives or
surface modifiers, flame speed additives, detergents, dehazers,
antiknock additives, metal deactivators, valve-seat recession
protectant compounds, dyes, solvents, carrier fluids, diluents and
markers. Examples of suitable such additives are described
generally in U.S. Pat. No. 5,855,629.
[0063] Conveniently, the fuel additives can be blended with one or
more solvents to form an additive concentrate, the additive
concentrate can then be admixed with the base gasoline or the
gasoline composition of the present invention.
[0064] The (active matter) concentration of any optional additives
present in the base gasoline or the gasoline composition of the
present invention is preferably up to 1 percent by weight, more
preferably in the range from 5 to 2000 ppmw, advantageously in the
range of from 300 to 1500 ppmw, such as from 300 to 1000 ppmw.
[0065] Lubricant compositions for use in the spark ignition engines
described herein generally generally comprise a base oil and one or
more performance additives, and should be suitable for use in a
spark-ignited internal combustion engine. In some embodiments, the
lubricant compositions described herein may be particularly useful
in a turbocharged spark-ignited engine, more particularly a
turbocharged spark-ignited engine which operates, or may operate,
or is intended to operate, with an inlet pressure of at least 1
bar.
[0066] The present invention has been found to be particularly
useful in high calcium engine oil environments. Hence, the
lubricant compositions for use herein generally have a calcium
content of from 1200 ppmw to 3000 ppmw, on the basis of the total
lubricating composition. In one embodiment, the lubricant
compositions for use herein have a calcium content from 2000 ppmw
to 3000 ppmw, as measured according to ASTM D5185. In another
embodiment, the lubricant compositions herein have a calcium
content from 2500 ppmw to 3000 ppmw.
[0067] The fuel compositions may be conveniently prepared using
conventional formulation techniques by admixing one or more base
fuels with one or more performance additive packages and/or one or
more additive components.
[0068] To facilitate a better understanding of the present
invention, the following examples of certain aspects of some
embodiments are given. In no way should the following examples be
read to limit, or define, the entire scope of the invention.
Examples
[0069] Two different fuels were used in the present examples.
Example 1 (according to the present invention) was a base fuel in
combination with a fuel additive package containing a combination
of detergents meeting the requirements of claim 1 herein. The base
fuel used in Example 1 was an E10 fuel (10% v/v ethanol) containing
16.9% v/v aromatics, 7.3% v/v olefins and 75.8% v/v saturates (all
results determined according to ASTM D1319), and having an
anti-knock index ((RON+MON)/2) of 93. The base fuel was obtained
from a US terminal and therefore met the ASTM D4814 specification
as required by regulations. Comparative Example 1 was the same base
fuel as in Example 1 in combination with an additive package
typically used in a market-average LAC gasoline. (LAC denotes
Lowest Additive Concentration). It is mandated by the U.S.
Environmental Protection Agency for all gasoline sold in the US to
have a minimum concentration of detergent, and it is common for the
gasoline with the minimum concentration of detergent to be called
LAC gasoline. Comparative Example 1 and Example 1 contained the
respective fuel additive packages at the same treat rates,
eliminating any changes in LSPI measurements due to the change in
treat rates of the additive packages.
[0070] Example 1 and Comparative Example 1 were subjected to the
following test method for measuring LSPI events and the frequency
thereof.
Test Method for Measuring LSPI
[0071] The test protocol used for measuring LSPI events involved
running a quasi-steady state test on a modern turbocharged gasoline
direct injection engine with a displacement of 2.0 L. The test
included operation at an engine condition where the low speed
pre-ignition phenomenon was known to occur. At this condition the
engine controls were fixed to prevent distortion of the results by
the engine settings. For this condition, the engine was held at
steady conditions for 25,000 engine cycles (one test segment). Each
test sequence consisted of six such test segments and was four
hours long. The test sequence was run two times for each fuel
without an oil drain or a flush in between. Therefore, each test
for each fuel was eight hours long and had 12 segments of 25,000
engine cycles each. The LSPI measurements in each test were done
during these 25,000 engine cycles test segments, when the
conditions were steady. The measurement metric for the test was to
measure the combustion pressure in all four cylinders of the engine
and to identify combustion cycles where low speed pre-ignition
occurred. Those cycles were counted and the total number of cycles
in which LSPI occurred per test was used to quantify the behaviour
of each fuel.
[0072] The following test conditions were used during the test:
1. The load (BMEP) and torque fluctuated slightly between tests
because the operating condition was defined by the fuel flow rate,
equivalence ratio, and CA50 location rather than the engine load.
2. The torque range in the two tests were between 250 Nm and 275
Nm. 3. BMEP varied between 15.8-17.3 bar. 4. Engine speed=2000 rpm.
5. Lubricant type: A GF-5 certified high calcium containing
lubricant of 5W-30 viscosity grade having a calcium content of 2900
ppmw as measured according to ASTM D5185.
[0073] Table 1 below sets out the total number of LSPI cycles per
test for the fuels of Example 1 and Comparative Example 1.
TABLE-US-00001 TABLE 1 Example: Total Number of LSPI cycles per
test Example 1 60 Comparative Example 1 98
[0074] The results in Table 1 show that the fuel of Example 1 was
associated with a reduced LSPI occurrence compared with the fuel of
Comparative Example 1. It is to be noted that each LSPI event in an
engine has the potential to result in a "mega knock," which is
characterized by extremely high pressures inside the engine
cylinder that could lead to a rapid and catastrophic degradation of
the engine. Therefore, the reduction in the number of LSPI cycles
obtained by Example 1, as shown in Table 1, is very
significant.
* * * * *